What about the effect of fevers on the brain makes fantasies so much more prescient, and dreams so much more realistic (in the sense of perception, not the content). Like seriously when I had a fever dream it was as real as real life, things were curious and trippy, but I could see every detail and was almost surprised at the freedom of my body in it, that I was in a dream (I didn't know it at the time) but was moving as if awake. The psychologies of those around me were also more fleshed out and felt like real people with all their complexities. When I walked down the street I moved and thought at a normal pace.

It's almost as if it accelerates the processing of the brain.